That is one option that Bill suggests; however fitting 13" PI wheel trims to a 14" Stag steel wheel causes the valve stem being bent over, which could in turn cause premature failure which you wouldn't want on the road...! That is why Stag rostyle trims had an oval hole for the valve stem as opposed to the round hole on the PI wheel trim. If going down the Stag steels route, then I'd fit Stag wheel trims - they are relatively easy to find. I saw several at Stoneleigh a couple of weekends ago...the beauty is most sellers don't know the difference which keeps the price down

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Incidentally, for anyone who maybe interested, My Tyres have now stocks of Maxxis 185 80 13 tyres at the best price I could find anywhere - I only know because I purchased a set this morning!
£116.19 each delivered, excluding fitting - far cheaper than Vintage Tyres at £109 each + vat and possibly delivery on top (£130.80 delivered on EBay), or BuyCarParts at £114.18 each but with delivery costs on top.
Register Member no. 1596
1967 Mk1 2000 in Gunmetal Grey
1969 Mk1 2000 in Royal Blue
1970 Mk2 2000 in Valencia Blue
1972 Mk2 2.5 PI in Triumph White
1973 Mk2 2.5 PI in Sienna Brown
1976 Mk2 2500S in Carmine Red